The CBI is relying on a 91-page letter from Kunal Ghosh to the Enforcement Directorate, detailing the role of Rajeev Kumar in handling the ponzi scam probe after the main accused, Sudipta Sen and Debjani Mukherjee, both promoters of Saradha Group of companies, had fled to Kashmir.

On Day 2 of its interrogation of Kolkata Police Commissioner Rajeev Kumar, the Central Bureau of Investigation (CBI) may confront him with former Trinamool Congress MP Kunal Ghosh.

Rajeev Kumar is being questioned by the CBI in its office in Shillong. He is being interrogated for his alleged role in withholding and tampering important documents in the Saradha and Rose Valley Chit Fund scams in West Bengal.

On Saturday, Rajeev Kumar was grilled for nearly nine hours by a three-member CBI team that had flown from Delhi.

The CBI will also question former Trinamool Congress MP Kunal Ghosh who is a co-accused.

5 things to know:

1) Rajeev Kumar is appearing before the CBI at its Shillong office following a Supreme Court order last week. The court had restrained the CBI from arresting Kumar and asked Kumar to cooperate with the agency in its agency. This was after an unprecedented showdown between the CBI and West Bengal Chief Minister Mamata Banerjee, who prevented a CBI team from interrogating Kumar in Kolkata last Sunday. (Read more about it here).

2) Trinamool Congress's Meghalaya coordinator and Rajeev Kumar's counsel Biswajit Deb said he [Kumar] is "cooperating and complying" with the CBI, news agency PTI said in a report. "He (Kumar) has come here on the orders of the Supreme Court. He has complied earlier and he is complying now as per the orders," he told reporters outside the CBI office.

3) Kumar's role is under the CBI's scanner because he was heading the special investigation team (SIT) that was formed by the West Bengal government to investigate the Saradha and Rose Valley Chit Fund scams. The investigation was later handed over to the CBI. The CBI alleges that when the investigation was handed over to it, Rajeev Kumar withheld some crucial and incriminating documents that the SIT had collected in the chit fund scams probe. The BJP alleges that these documents raise fingers at various TMC leaders and people close to Mamata Banerjee.

4) News agency PTI said that on Sunday, the CBI may confront Rajeev Kumar with Kunal Ghosh. But a final call on this will be taken by the investigating officer present in Shillong.

5) "The CBI is relying on a 91-page letter from Ghosh, who was expelled by TMC, to the Enforcement Directorate, detailing the role of Kumar in handling the ponzi scam probe after the main accused, Sudipta Sen and Debjani Mukherjee, both promoters of Saradha Group of companies, had fled to Kashmir," PTI said in its report.